1. Field of the Invention
This invention relates to hydrocarbon conversion in the presence of a crystalline aluminosilicate catalyst. More particularly, this invention relates to a process for converting hydrocarbons with a catalyst of ZSM-35 zeolite having an ultimate particle diameter of 0.005 to 0.1 micron as crystallized.
2. Description of the Prior Art
The crystalline aluminosilicate zeolite ZSM-35 and conversion of hydrocarbons in the presence thereof is more particularly described in U.S. application Ser. No. 528,061, filed Nov. 29, 1974, the entire contents of which are incorporated herein by reference. This zeolite, as synthesized, can be identified, in terms of mole ratios of oxides and in the anhydrous state, as follows: EQU (0.3-2.5) R.sub.2 O : (0-0.8) M.sub.2 O : Al.sub.2 O : Al.sub.2 O.sub.3 : &gt; 8 SiO.sub.2
wherein R is an organic nitrogen-containing cation derived from ethylenediamine or pyrrolidine and M is an alkali metal cation, and is characterized by a specified X-ray powder diffraction pattern. Catalyst containing ion exchanged ZSM-35 crystals have been found to be useful in petroleum processes such as upgrading the octane number of naphthas and reformates, catalytic dewaxing of petroleum fractions, reduction in the pour point of distillate and residual fuel oils, reduction in the freeze point of jet fuels, alkylation of aromatics with olefins, aromatization of normally gaseous olefins and paraffins, aromatization of normally liquid low molecular weight parrafins and olefins, isomerization of aromatics, paraffins and olefins, disproportionation of aromatics, transalkylation of aromatics, oligomerization of olefins and as a component for cracking catalyst. All of the foregoing catalytic processes are of value since they result in upgrading of the hydrocarbon charge being processed.
Along with other zeolite catalysts, those containing ZSM-35 have experienced a decline in catalytic activity with the duration of their use. Those skilled in the art of petroleum processing have sought means for extending the useful life of zeolite-containing catalysts. It would, as those in the art are aware, be of considerable practical advantage to retard the aging of a ZSM-35 containing zeolite catalyst during its use in hydrocarbon processing.